1. Field
Example embodiments of inventive concepts relate to systems on chips (SoCs), for example, to methods of controlling operating clock signals provided to function blocks in SoCs, SoCs using the method and/or semiconductor systems including the SoCs.
2. Description of Related Art
A system-on-chip (SoC) is semiconductor integration technology for implementing relatively complicated components having different functions in a single system. A SoC includes a processor, which controls the entire system, and various intellectual properties (IPs) controlled by the processor. Here, an IP is a circuit, a logic or a combination thereof, which can be integrated into the SoC. Code may be stored in the circuit or logic.
Systems including a SoC having a plurality of various IPs are usually driven by a battery. Consequently, low-power design is relatively important. When a reference clock signal is provided to the SoC by, for example, a phase locked loop (PLL), each of the IPs operates in response to an operating clock signal having a different frequency according to its function.
Each IP may be in an active state or an idle mode according to the function of the IP. And, different IPs may operate in different modes (e.g., idle or active) concurrently or simultaneously.
When at least one IP is in the active state and at least one IP is in the idle mode, an operating clock signal for the active state is applied to the at least one IP in the idle mode as if the IP in the idle mode is in the active state. In this instance, the SoC consumes unnecessary power. The unnecessary consumption of power may affect the lifespan of a battery, for example, when a frequency of several hundreds of MHz to several GHz is used.